Drill-holding device for rock-drilling engines



No 626,762. Patented lune I3, I899.

J. 6. 'LEYNER. I DRILL HOLDING DEVICE FOR RDDK DRILLING ENGINES.

(Application filed. June 14, 1898.) an Modem" UNITED STATES PATENTOFFICE.

JOHN GEORGE LEYNER, OF DENVER? COLORADO.

DRILL-HOLDING DEVICE FOR Rock-DRILLING ENGINES.

SPEGIFICATION formingpart of Letters Patent No. 626,762, dated June 13,1899.

,such as will enable others skilled in the art to which it appertairisto make and use the same, reference being had to the accompany:

ing drawings, and to the letters and figures of reference markedthereon, which form a part of this specification.

My invention relates to improvements in rock-drilling engines; and theobjects of my invention are, first, to provide a device for holding .andconfining against displacement a rock-cutting drill-bit in arock-drilling engine that is arranged to rest loosely and unclampably inoperative position in the drilling-em gine; second, to provide a devicethat'will confine a drill-bit within striking distance ofi and withinstriking relation. to the drillingengines' piston at all times and thatcan be used or not at the will of the operator, and, third, to provide aresilient cushioning device for confining at the will of the operator arock-cuttin g drill-bit within operative striking distance of the pistonor blow-delivering member and mechanism of a rock-drilling engine. Iattain these objects by the mechanism illustrated in the accompanyingdrawings, in which' Figure 1 is a longitudinal section of 'my in ventionand ofsuch parts of an air or steam drilling-engine as are necessary toillustrate my inventioin Fig.2 is a section on line A- of Fig.1; Fig. 3,a section on line B of Fig. 1. Similar letters and numerals of referencerefer to similar parts throughout the several. vlews.

Referring to Fig. 1, D designates the cylinder, and E the piston,of arock-drilling engine.

I have preferably illustrated my drill-bitholding device applied to adrilling-enginewhich ejects the rock-cuttings from'holes in rock whiledrilling them and in which i the drill-bit is heldlooselyandunclampably. My invention may be used to hold a drill-bit of any type ofrock-drilling engine in which the drill-bit is loosely supported and isstruck by Application filed June 14, 1898. erial No. 633,400. (Nomodel.)

the piston; A'fulldescription of the typeof engine I refer to isshown inapPlicationSerial No. 654,954, as only such parts are illustrated in theaccompanying drawings as are located around and adjacent to mydrill-holding collet. The cylinder is provided with a frontcylinder-head 2, which is threaded to the end of the cylinder. :A sleeve3 is rotatively mounted in the axial bore 4 of the cylinder-head. At itsinner end the sleeve has an enlarged round flange portion 5, whichprojects and fits loosely into a counterbore in the inner end of thecylinder-head. The flange portion of the sleeve is larger in diameterthan the bore of the cylinder, and its inner end bears against thebbttomof the counterbore in which'the cylinder-head screws. Between theopposite side of the flange and the bottom of the counterbore and aroundthe body of the sleeve I place a steel buffer-ring 6, which is providedwith a key portion 7, that fits loosely into a keyway 8 in thecylinder-head to prevent its turning on the sleeve. A rubber buffer-ring9 is also placed at'the side of the steel ring, anda second steel ring10 is placed on.the opposite side of the rubber butter-ring inthe bottomof the counterbore. These rings are adapted to cushion the blows of thepiston that strike against the end of the sleeve, .which happens whenthe engine is running against rock. From the flange-head of the sleeveone or more rods 11 project and extend loosely into a'hole 12 drilledinto the piston. The entrance to this hole is provided with a bushing18', in which the rods fit slidably.

and the drill-bit is-not in striking position I The pistonreciprocateson this rod, which is rigidly secured to the sleeve, andthrough the medium of the riflebar 14 and these rods the pistonrotatively turns the sleeve step by step. The means for turning thepiston step bystep is illustrated in myUnited States Patent No. 568,089.Axially through the rifle-bar from end to end I drill a hole 15 and alsoaxially through the striking end ofthe piston a similar-sized hole 16.through the rifle-bar and piston into a hole 19 drilled axially throughthe drill-bit 20 from end to end, which is larger in diameter than theend of thetube. The end of the tube is preferably reduced in diameter toadaptit to A tube 18 projects axially a short distance and is enoughsmaller to leave a clear space all around it for the ingress of theactuating fluid from the cylinder into the hole in the drill-shank.

A drill-bit may be used with my drill-holdingcollet of any of thecustomary forms of drill-steel in use. The drill-bit is illustratedasupset at one end 21, and they may be formed and sharpened into any oneof the several cutting-points used for rock-drill bits, as

they are made with one, three, or more'chiseledges.

The striking end 22 of theshank projects through the sleeve 3 into thecylinder and into the reciprocal path of the piston, which impingesagainst it at each full stroke. The striking end is preferably formedinto a polygon of preferably five sides for several inches from the end.At the termination of the polygonal end a portion 23is preferably turnedround, and these two portions at this end are a trifle longer than thelength of the sleeve, which is provided with an axial bore 24, that isformed partially round and partially of a similar polygonal form as thestriking end of the drill-shank. The bore of the sleeve is made to fitthe polygonal end and round portion ofthe striking end of the shank witha loose but snug fit. The drill shank is provided with a collar 25 atthe end the cylinder.

of said round portion which bears against the end of the sleeve anddefines the inward movement of the shank of the drill-bit into Thedrill-bit rests loosely and freely in the sleeve and cylinderhead and isnot clamped or bolted to them, and consequently is free to be insertedvinstantly in them or to be withdrawn instantly from them by theoperator. The sleeve does not extend quite to the end of the bore of thecylinderhead, a short space being left in which the collar of thedrill-bit extends. I The sleeve 3 is surrounded by'a collet 26, whichalso pro 'jects into the bore of the cylinder-head;

This collet is provided with a thread on its inner end, on which isscrewed a nut 27. A coiled expansive spring 28 surrounds the collet andis seated in a counte'rbore 29, formed on the cylinder head, which isadapted to receive it. The expansive spring resiliently holds the colletin itsnormal position in the cylinder-head aroundthe rotative sleeve. Inorder to secure the nut 27 to the collet against unscrewing, I drill ahole 30 through both nut and collet and drive a pin 31 in it, as shownmore ,clearly in Fig. 3. In order to drive this pin out-when wishing totake out the collet from the cylinder-head, I provide a hole 32in thecylinder-head in a position to register over the plum in line with thepin, in whicha smaller pinmay be inserted to drive the pin 31 out of thenut and collet. In order to do this, the cylinder-head must bedisengaged from the cylinder and the sleeve and drill-bit be first takenout of it. The collet projectsforwa'rd beyond the face of thecylinderdiead'far enough to allow a staplepin 33 to be inserted throughits projecting end and straddle the drill-bit at a short dis tance infront of the collar of the drill-bit.

'til its collar strikes the staple without any forward feeding movementof the cylinder. The staple-pin, as shown in Fig. 2, is inserted inholes 34, that are positioned close to opposite sides of the drill-shankand that extend clear through the collet, and the staple-pin projectsclear through the collet, and its two prongs extend across and almosttouch oppo-' site sides of the shank of the drill-bit andpresent a rigidabutment to the collar. "The cylinder should be fed forward just fastenough when drilling rock to keep the collar of the drill-bitsubstantially close to the end of the sleeve or midway between thesleeve and.the staple-pin and with the cutting-point of the drill-bitfirmly pressed by the. feed against the rock, as the actuating fluid ofthe cylinder always moves-the drill forward until it bears against therock and holds it there before the-piston strikes it. Consequently whenthe piston does strike it it is resting against'the rock and only'cutsinto it as far as the blow of the piston drives it into it, which is buta trifle if therock is normally hard and'sound; but if theground is softand seamy the drill may be driven so.-

far forward by one blow that its striking end will be driven inside ofthe sleeve, where the piston cannot strike it, and if it sticks in ascam the air must be shut off and the drill backed andstar'ted over. Itis to prevent the drills being driven too far forward, and to preventits sticking in seams thatthe staple is used. It is not needed and isnever used where the rock is hard and sound. Consequently the staple ispositioned to give the drill-bit as much forward movement as possibleand still keep its striking end projecting into the cylinder far enoughto allow the piston to strike it and drive it forward, and when thecollar of the drill-bit is-against the staple and the drill is struck bythe piston the collet is also driven forward; but its expansive springand staple returns it and the drill-bit back to'its normal position, sothat.

the next blow of the'piston will strike the end 'IIO of the drill-bit,which if fed forward carefully,

even if driven from the end of the sleeve against the staple at everyblow of the piston, will cut a smooth round hole in any kind of badrock. 1 form the prongs of the staple eitheratriflewiderornarrowerthantheholes are apart, so that itavillhave to be sprung into them, and itsresilient tension when in the holes willassist to hold it in themagainst and after the staple is pushed into the holes they spring towardeach other after these shoulders pass beyond the lower. edge of theholes and the shoulders overlap the lower edge of the holes, as shown inFig. 2, and form projecting stops which efiectually lock the staple.against accidental displacement from the machine, while-at the same timepermitting it to be withdrawn from the collet easily by one hand of theoperator, for whenthe staple is pulled by its yoke portion the prongsreadily spring apart, as the shoulders are slightly beveled and willeasily slide back into the holes. The collet is not attached to thesleeve, but is mounted loosely on it and also fits freely in thecylinder-head and can and does revolve more or less with the sleeve.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is-- l. The combination in a rock-drilling engine, ofthe cylinder and the piston, with the front cylinder-head having arotative sleeve arranged to be turned step by step by said piston,-adrill-bit operatively supported by said sleeve, a collet surroundingsaid sleeve, an expansive spring arranged to resiliently hold saidcollet in normal operative position, an abutment collar or stop on saiddrill-bit arranged and adapted to receive and define the backward thrustof said drill-bit and a removable pin in said collet arranged to beengaged by said abutment collar or stop, substantially as described.

2. The combination in a rock-drilling engine of the cylinder, the pistonand the front cylinder-head with the sleeve supported therein, adrill-bit operatively supported by. said sleeve; a collet surroundingsaid sleeve, means for holding said collet resiliently in operativeposition in said cylinder relative to said drill-bit and sleeve and asuitable pin or key removably arranged in said collet to operativelyconfine said drill-bit to said sleeve, substantially as described.

3. The combination in a rock-drilling engine of the cylinder, thepiston, the front cylinder-head, with a water-conveying tube projectingfrom the rear cylinder-head with a drill-holding sleeve, revolublymounted in said cylinder-head; an axial bore through said sleeve, adrill-bit operatively supported by said sleeve and arranged to beoperatively rotated step by step by said piston and sleeve, and havingsaid drill-bit project into the reciprocal path of said piston andarranged to be impinged by said piston, a collet loosely mounted on saidsleeve, a spring arranged to hold said collet in operative relation tosaid sleeve and drill-bit, an abutment on said drillbit and a suitablepin or key removably secured in said collet and arranged and adapted tobe engaged by the abutment of said drillbit, whereby said drill-bit isheld in said sleeve against accidental displacement, substantially asdescribed.

4. The combination of the cylinder, front cylinder-head and the piston,with the sleeve having rods projecting into suitable apertures adaptedto receive them in said piston, the collet surrounding said sleeve, thenut threaded to its end, the expansive spring arranged bet-ween said nutand shoulder of 'said cylinder-head, the staple-pin and the drill-bitoperatively supported in said cylin the der-head by said sleeve, colletand staple-pin, I

substantially as described.

5. The combination in a rock-drilling engine, of the cylinder, thepiston and-the front cylinder head containing a drill holding sleevearranged to be operatively rotated in said cylinder-head by said piston,a drill-bit operatively supported by said sleeve, a collet surroundingsaid sleeve, means for holding said collet in resilient operativerelation on said sleeve and having said collet arranged and adapted tohold said drill-bit within striking distance of said piston,substantially as described. I

6. The combination of the cylinder, the piston and the cylinder-head,with the sleeve and drill-bit, a collet loosely surrounding said sleeveand arranged and adapted to resiliently reciprocate axially in saidsleeve, a' thrust-' abutment on said drill-bit and a slip-pin in saidcollet arranged to be engaged by saidthrust-abutment, substantially asdescribed.

7. The combination of the cylinder and'the piston with the drill-holdingsleeve, the rods extending from the sleeve into said piston and thecollet and staple-pin, substantially as described.

8. The combination with the cylinder, the piston and the;frontcylinder-head, of the drill-holding sleeve; the rods secured thereto andextending into said piston, the hollow drill-bit provided with athrust-abutment, a collet surrounding said sleeve-and arranged toresiliently receive the concussion of said drill-bit and' the staple-pinarranged and adapted to be engaged by said thrust-abutment and toautomatically lock itself against accidental displacement from saidcollet, substantially as described.

9. The combination of the cylinder, the piston, and the cylinder-head,with the drillholding sleeve arranged to be rotated bysaid piston, thehollow drill-bit supported by said sleeve, the collet and itsstaple-pin, substantially as described. 3

10. The combination with the cylinder and the piston of the front"cylinder-head, the drill-holding sleeve, the drill-bit having a thrustabutment-collar and with a collet In testimony whereof iaflix mysignature mounted on said drill-holding sleeve in said in presence oftwo Witnesses.

cylinder-head and arran 'ed and adapted to e. T

confine said {l rill-bi t to aid sleeve against; I JOHN'GEORGE LE1 5inoperative displacement out of striking dis- Witnesses.

tance of said piston,- substantially as de- CLARENCE A; LAWSON,

scribed; r HARRSON G. THOMAS.

